haskell-holy-project: disable the test suite to fix the build

The test suite tries to access the network:

 | Test suite Tests: RUNNING...
 | All Tests
 |   [...]
 |   GithubAPI
 |     Yann:                              FAIL
 |       Exception: FailedConnectionException2 "api.github.com" 443 True getProtocolByName: does not exist (no such protocol name: tcp)
 |     Jasper:                            FAIL
 |       Exception: FailedConnectionException2 "api.github.com" 443 True getProtocolByName: does not exist (no such protocol name: tcp)
 |
 | 2 out of 16 tests failed (0.66s)
 | Test suite Tests: FAIL